Could all of you expects help me out please. I have a Canon Rebel XT and other than the original lens that came with the camera, I have a Canon 70 – 300 mm 4-5.6 IS USM lens. I would like to purchase an extender for the lens but I am being told that neither the Canon 1.4 or 2 is appropriate. Any suggestions for an extender?

The Canon extenders' front element protrudes out about 1/2 inch (12 mm), so they only mate with lenses with a recessed rear element, like the Canon L series tele-photos and a few L zooms.

I know people who've used the Kenko Pro converters and there's another brand (forgot the name at the moment) that also works OK, these will fit your lens.

But one problem you'll have is that the Canon consumer camera bodies (like your XTi) require f/5.6 or wider to auto-focus. If you add a 1.4x to your lens (which I think is f/4.5 - 5.6) you lose a stop so it's now an f/6.3 - 8 lens and it will not autofocus. With the 2x it's worse, f/9 - f/11.

If it really is a f/4 - 5.6 lens like you wrote then it will become f/5.6 - f/8, meaning when you add the 1,4x converter it will still AF at 70 mm (actually 98 mm with the 1.4x) but as soon as you zoom out and the aperture narrows you lose AF, so it's pretty much a bad idea all around.

Bill

Thanks for your response Bill. I guess I am hooped unless I buy a different lens. This trip to Africa in January is really a trip of a lifetime and I would love to get some wonderful wildlife photos. I guess I need to buy something else.

<b>I would love to get some wonderful wildlife photos.</b>

Last trip we took one guy's longest lens was a 300 mm (the rest of us had 500 mm's) and he did really well, so don't despair! What's more important is getting out early and getting good light (and getting lucky with sightings).

<b> I guess I need to buy something else.</b>

You might look at the costs of renting the 100-400 L IS lens for just this trip ... that's a nice combo with the 1.6x sensor sized Canon bodies, I feel. This would work better than buying an off-brand 1.4x converter, IMO. There were a couple of recent threads about shops that rented lenses.

Bill

IMHO, the camera and lenses you have will do fine. In fact, much better than fine. Equipment does not give you wonderful wildlife photos. The awful truth is that the photographer him/her self makes wonderful, or not, photos. Thinking that the camera makes good photos is like thinking a violin makes good music.

regards - tom
ps - on the other hand, if you have the $$$$, go for it.

I am in total agreement with Bill in his response to your question. Using an extender with your existing lens is not a good idea.

Also, I am a huge fan of the 100-400 lens and have used it to take a huge number of wildlife pictures with my Rebel XTi. It is very flexible, has good image quality, and is small enough to hand-hold and carry around easily. However, it does suffer in low light, particularly with respect to slow shutter speeds and spotty autofocus accuracy on small objects like birds, so you need good light for it to work at its best. You can see loads of example pictures with the XTi and 100-400 on my photo site, www.pbase.com/cwillis.

For a safari, my first recommendation for a &quot;one lens&quot; solution would be the 100-400. Another option you could consider is the Canon 300f4 lens. It is very sharp and a stop faster than the 100-400, so it would be better in low light than the 100-400. You could use a 1.4x extender with it and get a 420mm f5.6 lens as well and your camera will still autofocus. However, based on my own experiences, the zoom really helps to deal with the fact that wildlife can be large and close enough that you want to pull back sometimes and shoot at 100mm, or 200mm, and the 300f4 would not give you that option.

Whatever you do, be sure to practice extensively with your camera and lens before your trip. You will want to know how to set the camera for various situations and know what to expect in terms of its performance and limitations. So take a trip to a zoo and shoot some piotures to practice. We did that when we got our XTi last year, and it was time well spent when we got into the field.

Good luck and enjoy your trip!
Chris

Tom, I think of camera equipment as providing an &quot;envelope&quot; within with a good photographer can get good results. Better gear will not make you a better photographer nor guarantee you good pictures, but it will definitely expand the envelope in which you can credibly try. For example, I shoot bird pictures frequently with two friends who use 500/4's and 1.4xTCs, and I use my 100-400. If we get lucky and the birds are close up in good light, I can get good pictures of them. But for lower-light, more distant, or smaller subjects, there is no way I can even try to get a good shot. The 100-400 does not have enough reach for that, and the autofocus doesn't work as well because the lens is relatively slow.
So, while I agree that the photographer is the most important element in the equation, the equipment does make a big difference in setting the envelope in which you can try to get a great picture. The original poster's equipment is entirely satisfactory to get good pictures on a safari within the envelope in which it will function, but expanding that envelope to deal with more distant subjects or lower light requires something more in the way of lenses, I believe.

Chris

Thank you Chris and Bill. I live on Vancouver Island in Canada so there is not likely a place for me to rent a lens and there is no zoo. Looking at the cost of the 100-400 lens, I will just make sure my older Rebel XT and my existing lenses work to the best of our ability.

There are several places you can rent lenses by mail-order, like www.lensrentals.com, and www.borrowlenses.com. They ship the lenses to you and you ship them back when finished, and the rental rates are reasonable. I think there are a couple of other places that do this as well, but I can't remember the names off-hand.

Buying a new lens for a trip is an off-putting proposition, which is why these lens rental places are so popular. If that is within your inclination and budget, you might want to give it a try, otherwise just have a great time, as you will have better camera equipment than most of your safari compatriots anyway!

Chris

Chris, agree with you 100%. And unless someone can demonstrate that they know their equipment's &quot;envelope&quot; (like you certainly do) then they do not know how to use what they have. Or what they may be getting.

regards - tom

Chris, thank you for your rental suggestion. Just so that everyone knows, they do not offer rentals to Canadians due to the time that it takes to go through customs at the border.

mcpats,
There have been a number of good suggestion made here but one that may have been overlooked is the purchase of the 100-400 and reselling it later on Fred Miranda. I doubt it would cost you more than 75-100 dollars and you would be able to control when you receive the lens and when you resell, It is a well liked lens and one that is easy to sell for top dollar. There are less expensive solutions that will work but the quality is just much less. All but the better primes lose so much resolution, when used with extenders, that they disappoint most users. On the other hand, the 300mm L IS f4 prime will work well with the 1.4X TC. Whatever you decide, I would not put an extender-TC on the 70-300mm lens.
Regards-Chuck